Translate/Rotate/Scale helpers
you have many options for transformation manupilatoion :

Keyboard :


press  G or S or R for translation, scale and rotation 
chose the axis constraint X or Y or Z to limit the transformation on that axis
to limit the transformation to a plane you simply exclude the remaining axis, ex: to move on the XY plane press G than Shift+Z


Mouse :


select the appropriate manipulator in the 3D view 
click and drag along any axis





while holding the object you can trigger the axis constraint by midle mouse click and rotating to that axis :